Condition category
Nutritional, Metabolic, Endocrine
Date applied
Date assigned
Last edited
Retrospectively registered
Overall trial status
Recruitment status
No longer recruiting

Plain English Summary

Background and study aims
The ANKER-Study
In this randomized controlled clinical study, we investigated the effects of moderate mountain hiking and forest therapy on overweight couples with a sedentary lifestyle. The ANKER-Study will investigate possible effects on quality of life, quality of relationship, cardiorespiratory fitness, body composition, inflammation and balance.

Who can participate?
Overweight couples each aged between 50 and 65 years with a BMI of 25 to 30 and a sedentary lifestyle can participate in the ANKER-Study. Physical fitness for moderate mountain hiking tours is required.

What does the study involve?
Participants are allocated as couples by random into two groups: a nature-connection group and a hiking-group. Both intervention groups spend a 7-day holiday in Algund, Italy. The nature-connection group participates in five guided forest-therapy sessions and the hiking group undertakes in the meantime five guided mountain hiking tours. Medical examinations will be scheduled at the beginning of the 7 day holiday and at the end of the holiday in Algund, Italy. After 2 months a follow-up examination takes place in Salzburg, Austria. After 6 months, all participants will receive an online questionnaire. The medical examinations include a fitness test, measurement of body composition, questionnaires, differential blood count and measurement of skin parameters. All medical examinations will be performed by members of the Institute of Ecomedicine from the Paracelsus Medical University of Salzburg.

What are the possible benefits and risks of participating?
All study participants receive a 7-day holiday. A vacation improves mood and quality of life. As a negative side effect of physical activity, exercise-induced bronchoconstriction may occur.

Where is the study run from?
The Paracelsus Medical University of Salzburg (Austria)

When is the study starting and how long is it expected to run for?
October 2018 to October 2020

Who is funding the study?
The Tourism Association of Algund (Italy)

Who is the main contact?
Dr. Arnulf Hartl
Paracelsus Medical University Salzburg
Institute of Ecomedicine
Strubergasse 21
5020 Salzburg, Austria

Trial website

Contact information



Primary contact

Dr Arnulf Hartl


Contact details

Paracelsus Medical University Salzburg
Institute of Ecomedicine
Univ.Doz.Dr. Arnulf Hartl
Strubergasse 22
+43 (0)662 2420 80530

Additional identifiers

EudraCT number

Nil known number

Nil known

Protocol/serial number


Study information

Scientific title

Algunder Nature and Climate therapy: green Exercise vs. natuRe connection - The ANKER-Study



Study hypothesis

What are the possible effects of two different types of climate therapy for overweight couples? Do mountain hiking and forest therapy induce different physiological and psychological responses and how sustainable are these effects?

Ethics approval

Approved 13/03/2019, Ethics Committee of Bozen (Comprensorio Sanitario di Bolzano, Via Lorenz Böhler 5 39100 Bolzano; +39 0471908232;, ref: 18-2019

Study design

Randomized controlled trial with two intervention groups

Primary study design


Secondary study design

Randomised controlled trial

Trial setting


Trial type


Patient information sheet

Not available in web format, please use contact details to request a participants information sheet.


Couples who are overweight with a sedentary lifestyle


Particpants are randomized into one of two intervention groups:
The hiking intervention involves five guided hiking tours with an altitude difference ranging from 300 – 700m in altitude.
The nature-connection interventioninvolves five guided forest-therapy sessions. Each session was guided by a psychologist ( and lasted for 3-4 hours. The forest-therapy sessions included elements focusing on relationship, wellbeing and quality of relationship.

Randomization is performed by an open-source add-in (Daniel’s XL Toolbox, Ver. 7.2.7) for the Microsoft Excel spreadsheet software, with age, nature relatedness, BMI and activity level as allocation criteria. As allocation method Kullback-228 Leibler Divergence method was used.

Intervention duration for both groups is 7 days based in Algund. Examinations at baseline and 7 days take place at the Hospital of Meran. Examinations include a fitness test, measurement of body composition, questionnaires, differential blood count and measurement of skin parameters. One follow up takes place at 60 days at the Paracelsus Medical University Salzburg where the above examinations are repeated. A second follow up is scheduled at day 180 involving only an online questionnaire.

Intervention type



Drug names

Primary outcome measure

1. Health-related quality of life is measured using short form 12 health survey (SF12) and EuroQol (EQ-5D) health status questionnaire at baseline, 7, 60 and 180 days
2. Quality of relationship is measured using relationship questionnaire (Partnerschaftsfragebogen; PFB) and problem list (Problemliste; PL) at baseline, 7, 60 and 180 days

Secondary outcome measures

1. Body composition is measured using bio-impedance analysis (BIA) at baseline, 7 and 60 days
2. Cardiorespiratory fitness is measured using the Chester Step Test at baseline, 7 and 60 days
3. Balance is measured using the body stability check (MFT-S3) at baseline, 7 and 60 days
4. Inflammation is measured using using differential blood count and cytokine profile from serum or plasma at baseline, 7 and 60 days
5. Airway inflammation is measured using an exhaled nitric oxide (FeNO) test at baseline, 7 and 60 days
6. Skin quality is measured by transepithelial water loss at baseline, 7 and 60 days
7. Nature connection is measured using the Nature relatedness scale (NRS), Flourishing Scale (FS-D), Connectedness to nature scale (CNS) at baseline, 7, 60 and 180 days
8. Quality of life measured using the Satisfaction with Life Scale (SWLS) and Beschwerdeliste at baseline, 7, 60 and 180 days
9. Mindfulness is measured using the Mindful attention awareness scale (MAAS) and health-related control belief questionnaire (GKÜ) at baseline, 7, 60 and 180 days

Overall trial start date


Overall trial end date


Reason abandoned (if study stopped)


Participant inclusion criteria

1. Couples both aged from 50 to 65 years
2. Couples both with BMI between 25 and 30
3. Sedentary Lifestyle, International Physical Activity Questionnaire (IPAQ) score of <3.000 MET mins/week
4. Ability to participate in physical exercise (moderate intensive mountain hiking) as determined by the investigator

Participant type

Healthy volunteer

Age group




Target number of participants

120 participants, 60 couples

Participant exclusion criteria

1. Immunologically mediated chronic conditions or immunodeficiency
2. Severe respiratory disorders
3. Acute or untreated psychiatric disorders
4. Uncontrolled hypertension
5. Uncontrolled metabolic diseases
6. Acute infection or fever
7. Diagnosis of or treatment for malignant neoplastic disorders within the last 5 years
8. Arteriosclerotic event <6 months before enrollment
9. Cardiac insufficiency
10. Renal insufficiency
11. Diagnosis or history of alcoholism
12. Current recreational drug use
13. Currently smoking >10 cigarettes/day
14. Orthopedic contraindications for hiking
15. Medication intake >5mg/d Prednisone, Colchicine, Imuran, Methotrexate, Azathioprine, Cyclophosphamide or Cyclosporine
16. Intake of weight-loss drugs or preparations
17. Pregnancy

Recruitment start date


Recruitment end date



Countries of recruitment

Austria, Germany, Italy

Trial participating centre

Paracelsus Medical University Salzburg
Institute of Ecomedicine Strubergasse 22

Trial participating centre

Tappeiner Hospital Merano
Department of Sports Medicine Rossinistraße 5

Sponsor information


Paracelsus Medical University

Sponsor details

Research Office
Strubergasse 21
+43 699 14420095

Sponsor type




Funder type


Funder name

Tourism Association Algund

Alternative name(s)

Funding Body Type

Funding Body Subtype


Results and Publications

Publication and dissemination plan

Planned publication in a peer-reviewed journal

IPD sharing statement:
The datasets generated during and/or analysed during the current study are/will be available upon request from Dr. Arnulf Hartl, Paracelsus Medical University Salzburg, Institute of Ecomedicine, Strubergasse 22, 5020 Salzburg, Austria

Intention to publish date


Participant level data

Available on request

Basic results (scientific)

Publication list

Publication citations

Additional files

Editorial Notes

26/02/2020: The recruitment end date was changed from 31/03/2020 to 24/02/2020. 22/01/2020: Trial’s existence confirmed by the Ethics Committee of Bozen.